In many printing applications it is often necessary to use both laser and inkjet printing technologies to successfully produce a desired print job. For example, a print job comprising a multiple page document might include some pages with text only, some pages with color graphics only, and some pages which include both text and color graphics. To handle such or similar situations, a hybrid printer can be used in which "non-color" pages are printed by a laser print engine, the "color" pages are printed by an inkjet print engine, and the "combination color and non-color" pages are printed first by the laser print engine printing the black plane of a page and then by the inkjet print engine printing or imaging the color portion of the page (the latter which may include, inter alia, printing the color black). In such printer configurations the laser and inkjet print engines typically are aligned serially, although provision may be made for media to bypass the inkjet print engine in totally non-color print jobs.
Laser print engines generally are "non-stop" printing devices capable of very high media throughput. Print time for a laser print engine is for most practical purposes independent of the amount of data coverage on a page. Inkjet print engines, however, are generally "stop and go" printing mechanisms requiring significantly higher mechanical overhead. Print time for an inkjet print engine is a function of the amount and distribution of ink to be placed on a page. Typically, an inkjet print engine is capable of much lower media throughput as compared to a laser print engine.
Accordingly, one problem associated with a hybrid printer combining laser and inkjet printing technologies, particularly in situations in which the hybrid printer serves a plurality of networked computers, is throughput "bottleneck," i.e., an operating condition in which the laser print engine cannot print at up to its maximum capacity because it must wait for pages to clear out of the inkjet print engine. Such an operating condition represents an inefficiency which adversely impacts the overall rate of media throughput in the printer.